1. Technical Field
The present invention relates generally to an improved distributed data processing system and in particular to a method and apparatus for a distributed application comprising objects on clients and servers within the distributed data processing system.
2. Description of Related Art
Software developers face the fundamental problem that writing an enterprise-wide application is difficult and that writing a distributed application is even more difficult. In addition, an enterprise seeks to build an application as fast as possible without being locked into one platform. Ideally, enterprise developers would like to be able to write the application once and run it on all of their platforms. Enterprise JavaBeans™ technology seeks to provide this ability.
The Enterprise JavaBeans (EJB) component architecture is designed to enable enterprises to build scalable, secure, multi-platform, business-critical applications as reusable, server-side components. Its purpose is to solve the enterprise problems by allowing the enterprise developer to focus only on writing business logic.
The server-side environment and the tools needed to service it have greatly influenced the design goals for EJB technology. One key design goal was to reduce the process of building distributed applications as much as possible. This goal has been accomplished by turning features that ordinarily would need to be hand-coded into simple declarative properties of the Enterprise JavaBeans. These declarative properties generate a significant increase in development efficiency because certain behaviors, like security and transactions, are set, not in code, but are “flags” on the bean itself.
The EJB specification creates an infrastructure that takes care of the system-level programming, such as transactions, security, threading, naming, object-life cycle, resource pooling, remote access, and persistence. It also simplifies access to existing applications, and provides a uniform application development model for tool creation use.
Java provides a mechanism by which a Java client can invoke methods on a Java server that is running in a separate process using a methodology called Remote Method Invocation (RMI). However, if the server is not running in a Java environment, such as a CORBA-compliant (Common Object Request Broker Architecture) server, then the Java client cannot make any method calls to the method on the CORBA server since Java does not provide an inherent mechanism for communicating with CORBA objects.
Simply stated, CORBA is an Object Request Broker (ORB) that allows applications to communicate with one another no matter where they are located or who has designed them. An ORB is the middleware that establishes the client-server relationships between objects. Enterprises have turned to CORBA as a solution to provide inter-operability between various software applications.
There is no standard mechanism for performing data marshalling, i.e., data conversion for different types of data, between a Java client and a CORBA server. It would be advantageous to have a mechanism that allows a Java client to communicate with another Java application, such as an EJB, running in a non-Java environment, such as a CORBA server.